The Effects of Salicylic Acid Applications on miRNA Expression in Wheat Cultivars under Drought Stress

Wheat cultivation in Turkey, is highly affected by environmental factors such as drought stress, which reduces yields significantly. Applying chemicals that stimulate plant growth is an easy, low-cost, low-risk and effective approach to increase stress tolerance, and salicylic acid is prominent in adapting plants to adverse environmental conditions such as drought stress, salinity, and improving plants' tolerance to stress. In the study, Gün 91 and Ankara 98 cultivars were used as drought tolerant and Ankara 98the sensitive plant material, respectively. Two different doses (0.1 mM, 0.5mM) of salicylic acid (SA) were applied to these plants. Drought stress teratment was performed one week after SA application. Total RNAs were isolated from leaf samples collected from application and control pots. The expression levels of miR156, miR169, miR172, miR319, mir398 and the genes targeted by these miRNAs were determined. According to the results, in Gün 91, the expression levels of miR156 and miR172 was found higher in leaf tissues treated with SA under drought stress conditions. On the other hand, the level of miR169 was higher in Ankara 98. In Gün 91, miR319 expression level was higher in 0.5 mM salicylic acid + drought treatment, whereas in Ankara 98 was higher in 0.1 mM SA + drought treatment. According to the control group, mir398 expression level decreased significantly in both 91 and Ankara 98 plant groups in which SA + drought stress was applied together. As a result of this study, it was emphasized that salicylic acid is an important signal molecule in response to stress and it mitigates the effect in stress conditions, and the tolerance mechanism of drought tolerant and sensitive cultivars with salicylic acid application were different.